How to start and learning texturing
Purpose of the Model

Before you start with creating materials you should know the differences between the different purposes of a model. There are three main categories - still renders, animations and RT game engine models/assets. 

Still Renders

If you are aiming for rendering a single scene, that one particular scene frozen in time, you definitely want to use procedural material setups. And you definitely want to go crazy with them, because you want to achieve the best possible effect. This concerns not only realistic materials, all the materials of a scene should also match in style. 

Since your PC "only" needs to render one image, complicated material setups that put heavy load on CPU/GPU aren't much of a deal, it's the result that matters.

Animation Rendering

If you plan to render animations for movies, you still might want to use procedural materials, but keep in mind that your PC needs to render a ton of images for every minute you have in the end in your movie clip. 

The more complex your material setup, the more time it takes to render all the images you'll need for a short movie clip and in the end you might not even see all the details due to moving  characters and cameras. 

Real Time Game Engine Models and Assets

Most game engines today still use texture maps for materials, because even the fastest hardware isn't capable of creating a real-time animated game world with procedurally generated materials. 

You can still use procedural materials during the creation process of your model but you'll need to bake them to texture maps, before exporting and importing the model into a game engine. 

Rendering Engines

Blender offers two render engines "out of the box". The modern one is called Cycles, offers node-based material setups and also an "unbiased" modern approach to lights and shadows. Blender internal render engine takes a 
"biased" approach on rendering, which means that it simply ignores the more complicated functions regarding lights and shadows. 

While both render engines can produce still images and animations, I highly recommend using Cycles for that purpose. Blender Internal on the other side has the advantage to give a decent preview of game assets. 

You can read more about the differences and the technical background in Gandalf's answer

How to proceed

(All the points below come from personal experience. Yours or that of other people might be different. )

The non-Blender related answer is that you will need a lot of patience and determination to achieve good results. 


Start small, with basic models, shapes and materials.
Get the materials to look the way you want them to look. 
Do not aim for the moon at your fist shot, because landing between the stars early on can be very frustrating. 


The Blender-related answer is the above, plus 


the recommendation to look for tutorials all over the internet. 
Watch Blender related videos on youtube and vimeo and also keep in mind that you want to watch those which are related to your goal (first point - purpose of the model). 
There are some "big names" in the Blender community, like Andrew Price and Gleb Alexandrow. But you also find lots of bits and pieces of information from other people, sometimes just by watching them speedmodeling.